I installed Kubuntu 7.04 and used new instruction on scim/skim website to 
turn on skim using im-switch. The problem is gone. 

The original problem might be associated with a config file 
/etc/X11/Xsession.d/75custom-scim_init
which I added following some old instructions to turn on skim/scim. I 
deleted this file and use the im-switch to turn on skim/scim, and the 
problem is solved. 

The old config file probably contains: 
export XMODIFIERS="@im=SCIM"
export GTK_IM_MODULE="scim"
export XIM_PROGRAM="scim -d"

im-switch added a new file, 80im-switch in /etc/X11/Xsession.d/. 

These are the scim related packages I installed: 
dpkg -l scim*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-files/Unpacked/Failed-config/Half-installed
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: 
uppercase=bad)
||/ Name           Version        Description
+++-==============-==============-============================================
ii  scim           1.4.4-7ubuntu1 smart common input method platform
ii  scim-anthy     1.2.1-1build1  SCIM IMEngine module for Anthy
un  scim-canna     <none>         (no description available)
un  scim-chewing   <none>         (no description available)
un  scim-chinese   <none>         (no description available)
un  scim-config-gc <none>         (no description available)
un  scim-config-so <none>         (no description available)
un  scim-frontend- <none>         (no description available)
ii  scim-gtk2-immo 1.4.4-7ubuntu1 GTK+2 input method module with SCIM as 
backe
un  scim-hangul    <none>         (no description available)
un  scim-m17n      <none>         (no description available)
ii  scim-modules-s 1.4.4-7ubuntu1 socket modules for SCIM platform
ii  scim-pinyin    0.5.91-0ubuntu smart pinyin IM engine for SCIM platform
un  scim-prime     <none>         (no description available)
ii  scim-qtimm     0.9.4-0ubuntu5 SCIM context plugin for qt-immodule
un  scim-server-so <none>         (no description available)
un  scim-skk       <none>         (no description available)
un  scim-tables-ad <none>         (no description available)
un  scim-tables-ja <none>         (no description available)
un  scim-tables-ko <none>         (no description available)
un  scim-tables-zh <none>         (no description available)
un  scim-uim       <none>         (no description available)

dpkg -l skim*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-files/Unpacked/Failed-config/Half-installed
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: 
uppercase=bad)
||/ Name           Version        Description
+++-==============-==============-============================================
ii  skim           1.4.5-1ubuntu1 smart common input method platform for 
KDE
ii  skim-scim-piny 0.5.91-0ubuntu Skim support for Smart Pinyin IMEngine

I am not sure this problem has anything todo with some of the scim packages 
or not. 


On Monday 25 June 2007, SimSQ wrote:
> Just tried disabling SCIM. I think I can reproduce it with much better
> certainty than the kate bug.
>
> Steps to reproduce (working one)
> 1) command 1:
> $ XMODIFIERS= kdesktop_lock --forcelock
>
> 2) Wait 10-20 seconds. --> doesn't work if I don't wait
> 3) Press spacebar.
> 4) Type your password (it works!)
>
> 5) in the shell: $ XMODIFIERS=@im=SCIM kdesktop_lock --forcelock
> 6) Repeat (3), (4)
> 7) Type password (fails)
> 8) Try to <Tab> to shift focus to the Cancel button (fails)
> 9) Go to another terminal and kill kdesktop_lock.
> 10) Ponder.
>
>
> ** Changed in: scim (Ubuntu)
> Sourcepackagename: kdebase => scim